Now he is charged with restoring the 13-time Premier League champions to former glories after their disappointing seventh-place finish last season.

He told a news conference: "It's the biggest club in the world. Within two days I already know how important Manchester United is.

"In China, in Brazil, when I was coach of the Dutch team, people are talking about Manchester United.

"I have to work, I have to prepare a team and I have to adapt to this big club. It will not be easy, but I will do my best. Every season you have to prove that [you are the best] and last season you were seventh.

"When you see my career, you can see what I have won the future will show if I can do that again."

Van Gaal, who outlined his management principles before the World Cup, confirmed that ex-United players Nicky Butt, Paul Scholes and Phil Neville will all be given roles at the club.

But the former Bayern Munich, Barcelona and Ajax coach will take his time to assess his playing squad before deciding on making any additions.

"I want to look at the players here at present," Van Gaal said. "I know the players but I have not trained and coached them. It will take three or four weeks to see what they can do before we buy other players. Luke Shaw and Ander Herrera were already on the list and I approved them because I liked them."

There has been speculation about who will be named captain following the departure of Nemanja Vidic to Inter Milan.

Although Van Gaal declined to name a captain, with Wayne Rooney and Robin van Persie vying for the role, he said it was a position he takes seriously. "All players are candidates, so I will take five or six weeks," he said. "The captain's role is very important."